Adhesive resin composition

Abstract

The invention relates to an adhesive resin composition comprising an ethylene polymer having a melting point of 70 to 132 DEG C., a density of 0.88 to 0.94% g/cm3 and a melt flow rate (MFR) of 0.05 to 50 g/10 min. and/or a modified product thereof with an unsaturated carboxylic acid or its derivative (component A); a tackifier (component B); and a block copolymer containing at least one polymer block mainly composed of a vinyl aromatic hydrocarbon and at least one polymer block mainly composed of a conjugated diene or a hydrogenated product thereof (component C). This composition is useful as an adhesives showing excellent adhesion over a wide temperature range as well as processability by film molding, sheet molding, blow molding, etc. It is available for laminates comprising various kinds of resins such as polyolefins, styrenic resins, polyesters, acrylic resins and polyamides.

What is claimed is: 
     
       1. An adhesive resin composition for a multi-layered resin laminate, consisting essentially of a mixture of an ethylene polymer having a melting point of 70° to 132° C., a density of 0.88 to 0,945 g/cm 3  and a melt flow rate (MFR) of 0.05 to 50 g/10 min., and a modified product which is obtained by graft-modifying said ethylene polymer with an unsaturated carboxylic acid or a derivative thereof grafted thereto in an amount of 0.01 to 10 wt % (component A); a tackifier (component B); and a block copolymer containing at least one polymer block mainly composed of a vinyl aromatic hydrocarbon and at least one polymer block mainly composed of a conjugated diene or a hydrogenated product thereof (component C), wherein the contents of the components A, B and C are 40 to 70 wt %, 5 to 30 wt % and 5 to 30 wt %, respectively, based on the total amount of the components A, B and C. 
     
     
       2. The composition according to claim 1, which further contains at least one ingredient selected from the group consisting of an ethylene/α-olefin random copolymer having a melting point of not higher than 60° C., a density of 0.85 to 0.87 g/cm 3  and an MFR of 0.1 to 50 g/10 min., and a product obtained by graft-modifying said copolymer with an unsaturated carboxylic acid or its derivative (component D) in an amount of 1 to 50 wt % based on the total amount of the components A, B and C. 
     
     
       3. The composition according to claim 1, wherein said ethylene polymer has a melting point of 80° to 132° C., a density of 0.89 to 0.94 g/cm 3  and an MFR of 0.1 to 30 g/10 min. 
     
     
       4. The composition according to claim 1, wherein said ethylene polymer has a crystallinity, determined by X-ray diffraction, of 13 to 65%. 
     
     
       5. The composition according to claim 1, wherein said modified ethylene polymer is one produced by modifying said ethylene polymer with maleic acid or its anhydride. 
     
     
       6. The composition according to claim 1, wherein said modified ethylene polymer is one produced by graft-modifying said ethylene polymer with maleic anhydride and contains maleic anhydride grafted thereto in an amount of 0.05 to 7 wt %. 
     
     
       7. The composition according to claim 1, wherein said tackifier has a softening point of 70° to 150° C. 
     
     
       8. The composition according to claim 1, wherein said tackifier is selected from the group consisting of petroleum resins, rosin, terpene resins and hydrogenated products thereof. 
     
     
       9. The composition according to claim 8, wherein said petroleum resin is an aliphatic petroleum resin, an aromatic petroleum resin, or an aliphatic/aromatic petroleum resin which has a degree of hydrogenation of at least 80%. 
     
     
       10. The composition according to claim 1, wherein said block copolymer component C) comprises a styrene polymer block and a butadiene polymer block, an isoprene polymer block or a butadiene/isoprene polymer block. 
     
     
       11. The composition according to claim 10, wherein said block copolymer contains 10 to 80 wt % of a styrene polymer block. 
     
     
       12. The composition according to claim 10, wherein said block copolymer contains a butadiene or isoprene polymer block of which at least 90% is hydrogenated. 
     
     
       13. The composition according to claim 1, wherein said block copolymer has a number average molecular weight of 20,000 to 300,000. 
     
     
       14. The composition according to claim 2, wherein said ethylene/α-olefin random copolymer (component D) is an ethylene/propylene elastomer. 
     
     
       15. An adhesive resin composition for a multi-layered resin laminate, consisting essentially of a modified product which is obtained by graft-modifying an ethylene polymer with an unsaturated carboxylic acid or a derivative thereof grafted thereto in an amount of 0.01 to 10 wt %, said ethylene polymer having a melting point of 70° to 132° C. a density of 0.88 to 0.945 g/cm 3  and a melt flow rate (MFR) of 0.05 to 50 g/10 min. (component A); a tackifier (component B); and a block copolymer containing at least one polymer block mainly composed of a vinyl aromatic hydrocarbon and at least one polymer block-mainly composed of a conjugated diene or a hydrogenated product thereof (component C), wherein the contents of the components A, B and C are 40 to 70 wt %, 5 to 30 wt % and 5 to 30 wt %, respectively, based on the total amount of the components A, B and C. 
     
     
       16. The composition according to claim 15, which further contains at least one ingredient selected from the group consisting of an ethylene/α-olefin random copolymer having a melting point of not higher than 60° C., a density of 0.85 to 0.87 g/cm 3  and an MFR of 0.1 to 50 g/10 min., and a modified product obtained by graft-modifying said copolymer with an unsaturated carboxylic acid or its derivative (component D) in an amount of 1 to 50 wt % based on the total amount of the components A, B and C. 
     
     
       17. The composition according to claim 15, wherein said ethylene polymer has a melting point of 80° to 132° C. a density of 0.89 to 0.94 g/cm 3  and an MFR of 0.1 to 30 g/10 min. 
     
     
       18. The composition according to claim 15, wherein said ethylene polymer has a crystallinity, determined by X-ray diffraction, of 13 to 65%. 
     
     
       19. The composition according to claim 15, wherein said modified ethylene polymer is one produced by modifying said ethylene polymer with maleic acid or its anhydride. 
     
     
       20. The composition according to claim 15, wherein said modified ethylene polymer is one produced by graft-modifying said ethylene polymer with maleic anhydride and contains maleic anhydride grafted thereto in an amount of 0.05 to 7 wt %. 
     
     
       21. The composition according to claim 15, wherein said tackifier has a softening point of 70° to 150° C. 
     
     
       22. The composition according to claim 15, wherein said tackifier is selected from the group consisting of petroleum resins, rosin, terpene resins and hydrogenated products thereof. 
     
     
       23. The composition according to claim 22, wherein said petroleum resin is an aliphatic petroleum resin, an aromatic petroleum resin, or an aliphatic/aromatic petroleum resin which has a degree of hydrogenation of at least 80%. 
     
     
       24. The composition according to claim 15, wherein said block copolymer (component C) comprises a styrene polymer block and a butadiene polymer block, an isoprene polymer block or a butadiene/isoprene polymer block. 
     
     
       25. The composition according to claim 24, wherein said block copolymer contains 10 to 80 wt % of a styrene polymer block. 
     
     
       26. The composition according to claim 24, wherein said block copolymer contains a butadiene or isoprene polymer block of which at least 90% is hydrogenated. 
     
     
       27. The composition according to claim 15, wherein said block copolymer has a number average molecular weight of 20,000 to 300,000. 
     
     
       28. The composition according to claim 16, wherein said ethylene/α-olefin random copolymer (component D) is an ethylene/propylene elastomer.